G'day again guys,
I know questions like this one come up ALL the time, but so far I haven't found anything but suggestions about what backspace is ideal. I've spent days now trying to wrap my head around this and I can't figure it out, so I'm appealing to the hive mind.
I have a 06 Golden Eagle. It currently has 31x10.5 R15s on standard 15x7 ECCO rims. These seem to have P31.75 offset, and around 5.25 inch backspacing. If I measure from the body work to the widest part of the current flares, they measure at 5 inches and just cover the existing rubber.
I want to go to 33x12.5s and I'm trying to source suitable steel wheels. All the threads I have read say, forget about offset and use backspace. However all the wheels I can find on Aussie sites only give offset. So I've been using online calculators to try figure out what I need.
If I was to go up to 7 inch flares, it gains me about 2 inches of extra space to fit 12.5s under them. So here's my problem. I'm looking at 15x8 Sunraysia steelies, I can only seem to find offsets of N10 or N20. These both seem to put the backspacing into the sweet zone for 33x12.5s. Using online calculators it gives me the following information.
-10 Offset (4.11 inch backspace)
-20 Offset (3.71 inch backspace)
As you can see, according to this calculator both offsets pushes the outer edge of the tires beyond the 2" I have to play with to keep them legally covered by the flares. Obviously people successfully do this, so I'm not sure if I'm making a mistake somewhere or what.
Can someone please recommend some locally sourced 15x8 steelies with the appropriate offsets for me to fit these damn 33s?